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HDFS-11449: libhdfs++: Log Datanode read size when reading from an HDFS block. Contributed by Xiaowei Zhu.

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James 2017-02-24 10:46:50 -05:00 committed by James Clampffer
parent 606d20c6c0
commit 0f3f8db113
1 changed files with 4 additions and 3 deletions
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7
hadoop-hdfs-project/hadoop-hdfs-native-client/src/main/native/libhdfspp/lib/fs/filehandle.cc
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@ -227,14 +227,15 @@ void FileHandleImpl::AsyncPreadSome(
std::string dnIpAddr = chosen_dn.id().ipaddr();
std::string dnHostName = chosen_dn.id().hostname();
LOG_DEBUG(kFileHandle, << "FileHandleImpl::AsyncPreadSome("
<< FMT_THIS_ADDR << "), ...) Datanode hostname=" << dnHostName << ", IP Address=" << dnIpAddr
<< ", file path=\"" << path_ << "\", offset=" << offset);
uint64_t offset_within_block = offset - block->offset();
uint64_t size_within_block = std::min<uint64_t>(
block->b().numbytes() - offset_within_block, asio::buffer_size(buffers));
LOG_DEBUG(kFileHandle, << "FileHandleImpl::AsyncPreadSome("
<< FMT_THIS_ADDR << "), ...) Datanode hostname=" << dnHostName << ", IP Address=" << dnIpAddr
<< ", file path=\"" << path_ << "\", offset=" << offset << ", read size=" << size_within_block);
// This is where we will put the logic for re-using a DN connection; we can
// steal the FileHandle's dn and put it back when we're done
std::shared_ptr<DataNodeConnection> dn = CreateDataNodeConnection(io_service_, chosen_dn, &block->blocktoken());